Historically, acoustical speaker cabinets have been constructed of wood and wooden by-products such as particle board and plywood. In applications of live music broadcast where speaker enclosures may be constantly transported from performance to performance, there is provided herein an acoustically stable structural material which not only satisfies the need of structural integrity and durability but also allows for a minimum weight savings of at least 50% over conventional speaker enclosures. Suspended or so-called flying systems as utilized in large civic centers and auditoriums would be enhanced due to these lighter components reducing roof load stresses. Panels of the lightweight material herein are hand laminated into 48 inch and one hundred twenty inch sheets wherein construction and bonding is accomplished through the utilization of polyester resin, one and two part epoxy systems and hot melt adhesive applications.
The construction laminate detail hereinafter defined comprises a sandwich of twenty four ounce fiberglass roving with polyester resin impregnation on either side of a U190 urethane foam core. Polyester resin skin tie blocks are used as panel stiffeners and support anchors.